Application of the analog digital conversion circuit has become wider and wider. The analog digital conversion circuit can be applied in multi-channel/multi-input/multi-output. However, as for the conventional analog digital conversion circuit, in N channels situation, N analog digital conversion circuits will be needed (N being a positive integer). As the circuit area increases, more circuit costs will occur.
Thus, it is a prominent task for the industries to provide an analog digital conversion circuit, which does not increase circuit area or circuit cost significantly when used in multi-channel/multi-input/multi-output.